Aircraft with rotative wings



Sept. 4, 1928. 1,682,893

.1. DE LA CIERVA AIRCRAFT WITH ROTATIVE WINGS Filed Jan. 19, 1927 F/G.

atented Sept. 4, 1928.

UNITED STATES PATENT OFFICE JUAN D1. CIEBVA, OF MADRID, SPAIN.

AIRCRAFT WITH ROTATIVE WINGS.

Application filed January 19, 1927, serial No. 162,178, and in Great Britain January 25, 1926.

This invention relates to aircraft-bf the Ipe embodyin a wing system which roites freely. in ight by reason of the act on f the air flow on the wings and 1n which 1e wings are hinge-jointed to a member onstituting their common centre of rotaion in such a manner that during fl ght ach wing is tending to adopt at all times ositions in" which the centrifugal force due 3 rotation and the lift are in equilibrium.

If, however, the centrifugal component e too small the wings may incline upwards such an extent that their aerodynamical fficiency is impaired. To overcome this, entrifugal force may be increased by makng the wings heavier. It is obvlous howiver that the general efiiciency of the air- :raft would be reduced by unduly increasng the weight of the wings.

It has been found from observatlon of the movement of the wings in flight (made poss1 )le by slow motion kinematographic recrds) that the angle between any two d1- imetrically opposite wings pre-supposmg in'even number of wings) varies only a .imited extent in a complete revolut on. The wing advancing into the air flow rises whilst that wing moving with the air flow iescends, the angle between them remalmng more or less constant.

According to the present invention, in a supporting aerofoil system of the character referred to, diametrically opposite wmgs are connected or rendered interdependent that the vertical angle between them remains constant or approximately so during rotation.

This vertical angle will obviously vary ac cording to the characteristics of the wings and the aircraft. Usually it will be approximately equal to the mean angle which diametrically opposite wings would form with one another in a complete revolution if the wings were perfectly free to swing independently about their hinge-joints.

The invention may be applied 1n various constructional forms. as for instance by connecting oppositely disposed wings by means of a rigid or partially yieldable member.

A particularly advantageous form of construction however is one in which the supporting aerofoil system is constituted by a pair of wings disposed at a horizontal angle of 180 and rigidly interconnected as for example by constructing both wings on a common longitudinal spar or spars, the pair being centrally hinge-jointed to the rotative member connected to the body of the air-- craft in such a manner that the said wings may rock as a unit about the axis of the hinge joint in response to variations of aerodynamical pressure.

This arrangement has the advantage of extreme simplicity of construction and reduction of weight and it will further be obvious that the centrifugal stresses, in the case Where the pair of wings are constructed on a common longitudinal spar or spars, are taken by the' latter and not by the hingejoint bearings as in the case where each wing is independently hinge-jointed to the axis of rotation.

The ordinary separately hinged construction may be employed however with either a rigid or a yieldable connection between oppositely disposed wings, and in all cases the necessity is avoided of loading the wing tips or otherwise increasing the weight of the wing structure in order to maintain the requisite centrifugal component.

The accompanying drawings diagrammatically illustrate forms of construction in accordance with the present invention.

Figs. 1 and 2 are respectively an elevation and a plan view of one form in which a pair of wings are constructed as aunit.

Fig. 3 is a local view in elevation'partly in section of the hinge-joint.

Fig. 4 in a local view in plan illustrating an alternative construction in which the axis of the hinge-joint is inclined as hereinafter described.

Fig. 5 is an elevation of another form of construction employing independent hingejOialtS with a rigid wing connecting member, an

Fig. 6 is a similar view on a larger scale illustrating a yieldable connexion.

Referring to Figs. 1, 2 and 3:-

A pair of wings A and B are constructed as a unit on acommon longitudinal spar or spars with a suitable vertical angle m between them, in the general case equal to the mean angle the wings would form in a complete revolution were'they independently hinge-jointed. These wings are centrally hinged as a unit at C to a substantially vertical member D rotatably supported by the body of the aircraft, with any known or suitable form of mounting. a

Resilient blocks or buflers E carried by arms E are provided to prevent the wings inclining below a predetermined limit.

Since the Wings are rotative, the sense of rotation being shown by the arrow 3/ SlF'ig. 2), the leading edges A and B of t e wings are reversed with respect to each other. i

The hinge-joint is here shown as consisting of a pair of lugs F formmgbearings, which may be ball or other anti-friction bearings, for a pin G assing through a strengthened central section of the wings.

It will be seen that with this form of construction the centrifu al stresses due to rotation are taken along t e rigid wlng spar or spars and not by the hinge bearmgs.

In the form illustrated in Fig. 4 the axis of the hinge-joint is inclined viewed in tplan to the longitudinal axis of symmetry 0 the Wingsto effect an automatic var ation of aerod amical incidence as the win s rise and all during rotation. The inclination is such that the wing advancing against the air flow decreases its incidence as it rises, whilst the wing moving with the an flow increases its incidence as it descends and in this manner the range of variation of incidence in a complete revolution is diminished with a consequent increase of efiiciency.

In Fi .5 a pair of win s H and J are inde end ntly hinge-jointe to the rotative mem er K and are connected by a rigid strut L pivoted at its ends to the wings.

In the form shown in Fi 6 the connexions of the strut L to t e wings are spring mounted to allow the vertical angle between the wings to vary wlthln suitable limits.

What I claim is 1. In aircraft, a supporting system comprising an even number of reely rotative win s adapted to be driven by the relative air flown across them in flight, diametrically opposite wings being connected or rendered interdependent and flexibly jointed to the axis of rotation in such a manner that each pair of wings may oscillate under the influ ence' of centrifugal and lift forces in a plane substantially perpendicular to the plane of rotation.

2. In aircraft, a supporting system comprising an even number of freely rotative wings adapted to be driven by the relative air flow across them in flight, a rotative member connected to the body of aircraft and revolvable about a substantially vertical axis, flexible joints connecting the wings to said rotative member and yieldable elements connecting diametrically opposite wings in pairs in such a manner that each pair may oscillate under the influence of centrifugal and lift forces in a plane substantially perpendicular to the plane of rotation.

3. In aircraft, a freely rotative supporting stem com rising a pair of wings diamet fically oppd sitely disposed in the plane 0: rotation and rigidly connected together, 1 rotative member connected to the body 0: the aircraft and revolvable about a substan tially vertical axis, and a hinge joint con necting the pair of wings to said rotativi member so t lat said wings may rock as 1 unit about the axis of the joint under tln influence of centrifugal and lift forces.

4. In aircraft, a freely rotative sup ortin; system comprising a pair of wings 'amet rically oppositely disposed in the plane 0: rotation and adapted to be driven by th relative air flow across them in flight, both 0: said wings being constructed on a comma] longitudinal spar, a rotative member con nected to the body of the aircraft and re volvable about a substantially vertical taxi: and a hinge joint connecting the pair 0: wings to said rotative member so that suit win s may rock as a unit about the axis 0: the oint under the influence of centrifuga and lift forces.

5. In aircraft, a freely rotative sup rtim system comprising a pair of wings iamet rically oppositely disposed in the plane 0: rotation and rigidly connected together, a rotative member connected to the body 0: the aircraft and revolvable about a substan tially vertical axis, and a hinge joint connect ing the pair of wings to said rotative membe: so that said wings may rock as a unit abou the axis of the joint under the influence o: centrifugal and lift forces, the axis of tht hin e joint being inclined, viewed in lan to t e longitudinal axis of symmetry 0 thl wings in such a manner that during rotatiol the incidence of a rising wing decrease whilst that of a descending wing me 6. In aircraft, a freely rotative sup ortiq system comprising a pair of wings siamet rically oppositely disposed in the plane 01 rotation and adapted to be driven by tllt relative air flow across them in flight, botl of said wings being constructed on a common longitudinal spar, a rotative membel connected to the body of the aircraft and revolvable about a substantially vertical axis and a hinge joint connecting the pair 01 wings to said rotative member so that said wings may rock as a unit about the axis 01 the joint under the influence of centri I and lift forces the axis of the hinge joint being inclined, viewed in plan, to the 10 tudinal axis of symmetry-of the wings in such a manner that during rotation the incidence of a rising wing decreases whilst that of a descendin wing increases.

7. In aircraft, a supportin system comprising an even number of reely rotative wings adapted to be driven by the relative air flow across them in flight, diametrically opposite wings being connected or rendered interdependent and flexibly jointed to the and'revolvable about a substantially vertical axis, flexible joints connecting the wings to said rotative member and yieldable elements connecting diametrically opposite wings 15 in pairs in such a manner that each pair may oscillate under the influence of centrifugal and lift forces in a plane substantially perpendicular to the plane of rotation and limiting devices for preventing the wings 2 swinging too low.

JUAN DE LA CIERVA. 

